The objective of the proposed research is to apply knowledge gained from basic research to the understanding of human ocular motor disorders. Our effort emphasizes: 1) quantitative measurements of ocular motor function in human beings; and 2) the application of control system's analysis and computer simulation to help us understand the functional organization of the ocular motor system. We are carefully investigating selected groups of patients in the context of three models: 1) a model of the brainstem neural network that generates saccades for use in the study of patients with saccadic dysmetria and saccadic oscillations; 2) a model of visual following reflexes for use in patients with disordered visual tracking; and 3) a model of the mode of cooperation among extraocular muscles for use in diagnosis and management of paralytic and non-paralytic strabismus. We are also using these models to study central nervous system adaptation in patients with peripheral ocular motor nerve palsies.